Using your favorite editor, save this to a file named "hostloadcolour". If
you have the Bashprompt package installed, this will work as a theme. If you
don't, type source hostloadcolour and then hostloadcolour.
Either way, "prompt_command" becomes a function in your environment.
If you examine the code, you will notice that the colours ($COLOUR_HIGH and
$COLOUR_LOW) are set using only a partial colour code, ie. "1;34" instead of
"\[\033[1;34m\]", which I would have preferred. I have been unable to get
it to work with the complete code. Please let me know if you manage this.